I. Field of the Invention
This invention relates to a novel 1,2-dithiol-3-thione derivative having an immunomodulating property, to a process of producing the same, and to an immunomodulator composition comprising the same as an effective ingredient.
II. Description of the Prior Art
Immunomodulating action is understood as an action which scarcely influences an organism when the immune system of the organism is normally functioning, but which stimulates the immune system of the organism when the immune system is weakened, and which suppresses the immune system when it is hyperactive.
Hyperactivity of the immune system may be caused by the hypoactivity of immunosuppressive mechanism, while conversely, the hypoactivity of the immune system may be caused by the hyperactivity of the immunosuppressive mechanism. Thus, immunomodulation regulatively controls the fractuation of the immunosuppressive power of the immunosuppressive mechanism to normalize the mechanism.
Conventional immunomodulators such as levamisole and thymus hormones are reported to have a number of side effects when they are used clinically.
For example, levamisole is reported to have side effects such as vomiturition, eruption and hemotoxicity, as well as the most serious side effect of granulocytopenia. Although granulocytopenia is a side effect which disappears upon stopping the administration of levamisole, when it is continuously administered for a long time, the number of leucocytes must be strictly monitored.
Thus, an immunomodulator which does not have serious side effects is strongly demanded.
Recently, the necessity of an immunomodulator which prohibits the in vivo infection and growing of pathogenic parasites such as viruses and bacteria, while also strengthening the resistivity against endogenous alien matter such as cancer cells, is prominently increasing. Further, it is desired that such an immunomodulator also be used for curing various allergies, rheumatic arthritis, diabetes, immunodeficiency syndrome, multiple sclerosis and Guillain-Barre syndrome.
The present inventors have found that lipoic acid (DL-thioctic acid), which is widely used for curing hepatopathy, has an excellent immunomodulating effect, and published the discovery (Proceedings of Pharmaceutical Society of Japan, 104th Annual Meeting, p. 397 (1984)).